Light weight variable force restraint

ABSTRACT

An evacuation system may comprise an evacuation slide configured to be deployed from an aircraft, a first strap coupled to the evacuation slide, a second strap coupled to the evacuation slide, and a releasable restraint extending through the first strap and the second strap. The releasable restraint may comprise a first stem connected to a first bead and a second stem connected to a second bead, wherein a diameter of the second stem may be different from a diameter of the first stem.

FIELD

The present disclosure relates to inflatable evacuation slides and, inparticular, to restraint release systems and methods for restrainingevacuation slides.

BACKGROUND

Emergency evacuation slides may be used to exit an aircraft absent a jetway or other suitable means of egress for passengers. The slides maydeploy from a door sill or a side of the aircraft fuselage, for example.The slide deployment is controlled by restraints placed throughout thelength of the slide which release in stages in response to internalslide pressure.

SUMMARY

In various embodiments, a releasable restraint for an evacuation systemis disclosed. A releasable restraint for an evacuation system maycomprise a first stem connected to a first bead, and a second stemconnected to a second bead, wherein a diameter of the second stem isdifferent from a diameter of the first stem.

In various embodiments, the releasable restraint may comprise a singleunibody member. The single unibody member may comprise a femalefastener, a plurality of beads including the first bead and the secondbead, and a plurality of stems, including the first stem and the secondstem, connecting the plurality of beads, wherein the beads and the stemsare configured to allow the beads to move through the female fastener ina first direction while preventing the beads from moving through thefemale fastener in a second direction opposite of the first direction.The plurality of stems may be configured to be frangible at selectedtensile loads. The selected tensile loads may increase along the singleunibody member in the second direction. The releasable restraint may bein operable communication with the evacuation system and a diameter of astem connected to a last bead through the female fastener may define aload associated with releasing the releasable restraint duringdeployment of the evacuation system.

In various embodiments, the releasable restraint may comprise nylon. Atleast one of a color or a shape of at least one of the first bead or thefirst stem may indicate a tensile strength of the first stem and may bedifferent from at least one of a color or a shape of at least one of thesecond bead or the second stem. A ratio of the diameter of the firststem to the diameter of the second stem may be between 6:5 and 7:1.

In various embodiments, the releasable restraint may further comprise athird stem connected to a third bead, wherein a diameter of the thirdstem may be different from the diameter of the first stem and thediameter of the second stem.

In various embodiments, an evacuation system may comprise an evacuationslide, a first strap coupled to the evacuation slide, a second strapcoupled to the evacuation slide, and a releasable restraint extendingthrough the first strap and the second strap, the releasable restraintcomprising a first stem connected to a first bead and a second stemconnected to a second bead, wherein a diameter of the second stem isdifferent from a diameter of the first stem.

In various embodiments, the releasable restraint may further comprise afemale fastener configured to receive and retain a plurality of beads ofthe releasable restraint, the plurality of beads including the firstbead and the second bead, a diameter of a stem connected to a last beadreceived by the female fastener may define a load associated withreleasing the releasable restraint during deployment of the evacuationsystem.

In various embodiments, at least one of a color or a shape of the firstbead may indicate the diameter of the first stem and may be differentfrom at least one of a color or a shape of the second bead. The firststem may be configured to separate in response to a first tensile forceand the second stem maybe configured to separate in response to a secondtensile force greater than the first tensile force. The diameter of thefirst stem may be between 0.05 inches and 0.13 inches. The diameter ofthe second stem may be between 0.09 inches and 0.345 inches.

In various embodiments, a method for restraining an evacuation slide maycomprise extending a releasable restraint through a first strap coupledto the evacuation slide, and extending the releasable restraint througha second strap coupled to the evacuation slide, the releasable restraintcomprising a first stem connected to a first bead, and a second stemconnected to a second bead, wherein a diameter of the second stem isdifferent from a diameter of the first stem.

In various embodiments the method may further comprise configuring afemale fastener of the releasable restraint to receive and retain aplurality of beads of the releasable restraint, the plurality of beadsincluding the first bead and the second bead, wherein a diameter of astem connected to a last bead received by the female fastener may definea load associated with releasing the releasable restraint. The methodmay further comprise indicating at least one of a diameter or a tensilestrength of the first stem using at least one of a color or a shape ofthe first bead. A ratio of the diameter of the first stem to thediameter of the second stem may be between 6:5 and 7:1.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, the following descriptionand drawings are intended to be exemplary in nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the figures, wherein like numerals denotelike elements.

FIG. 1 illustrates a perspective view of an evacuation slide in adeployed position, in accordance with various embodiments;

FIG. 2 illustrates a perspective view of an evacuation slide in a stowedposition, in accordance with various embodiments;

FIGS. 3A, 3B, and 3C illustrate a restraint aiding in retaining anevacuation slide in a folded position, in accordance with variousembodiments;

FIG. 4 illustrates a restraint in an unlocked position, in accordancewith various embodiments;

FIGS. 5A and 5B illustrate a restraint in a locked position and in areleased position, respectively, in accordance with various embodiments;

FIG. 6 illustrates a method for restraining an evacuation slide, inaccordance with various embodiments.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes referenceto the accompanying drawings, which show exemplary embodiments by way ofillustration. While these exemplary embodiments are described insufficient detail to enable those skilled in the art to practice theexemplary embodiments of the disclosure, it should be understood thatother embodiments may be realized and that logical changes andadaptations in design and construction may be made in accordance withthis disclosure and the teachings herein. Thus, the detailed descriptionherein is presented for purposes of illustration only and notlimitation. The steps recited in any of the method or processdescriptions may be executed in any order and are not necessarilylimited to the order presented.

Furthermore, any reference to singular includes plural embodiments, andany reference to more than one component or step may include a singularembodiment or step. Also, any reference to attached, fixed, connected orthe like may include permanent, removable, temporary, partial, fulland/or any other possible attachment option. Additionally, any referenceto without contact (or similar phrases) may also include reduced contactor minimal contact. Surface cross hatching lines may be used throughoutthe figures to denote different parts but not necessarily to denote thesame or different materials.

Slides according to the present disclosure may extend from an aircraftstructure, such as a fuselage or a wing, for example, to an exit surfacein a fully deployed position. During deployment, a plurality ofrestraints may aid in controlling the inflation process of the slide.The restraints may be configured to de-couple in response to internalslide pressure. A releasable restraint is provided in variousembodiments. Releasable restraints, according to the present disclosure,may provide weight savings, reduced packaging density, decreased cost,and increased restraint dependability.

With respect to FIG. 2 through FIG. 5, elements with like elementnumbering, as depicted in FIG. 1, are intended to be the same and willnot necessarily be repeated for the sake of clarity. With respect toFIGS. 4, 5A and 5B, elements with like element numbering, as depicted inFIG. 3B and FIG. 3C, are intended to be the same and will notnecessarily be repeated for the sake of clarity. With respect to FIGS.5A and 5B, elements with like element numbering, as depicted in FIG. 4,are intended to be the same and will not necessarily be repeated for thesake of clarity.

With reference to FIG. 1, an evacuation system 100 is illustrated, inaccordance with various embodiments. Evacuation system 100 may comprisean evacuation slide 104. Evacuation slide 104 may comprise a head end106 and a toe end 108 opposite head end 106. Head end 106 may be coupledto an aircraft structure. Evacuation slide 104 may comprise aninflatable slide. FIG. 1 illustrates evacuation slide 104 in an inflatedand/or deployed position. Evacuation slide 104 may comprise a slidingsurface 110 and an underside surface 112 opposite sliding surface 110.Evacuation slide 104 may comprise a dual lane slide. However, evacuationslide 104 may comprise any number of lanes. Toe end 108 may contact anexit surface in response to evacuation slide 104 being deployed.

With reference to FIG. 2, evacuation slide 104 is illustrated in astowed and/or packed position. In this regard, evacuation slide 104 maybe stowed in a packboard 210. In various embodiments, evacuation slide104 may be folded in the stowed position. In various embodiments,evacuation slide 104 may be deployed from packboard 210 in response toopening an emergency exit door. Packboard 210 may be coupled to anaircraft in an installed position. Typically, a packboard 210 includes ablow-out panel which opens in response to deployment of evacuation slide104, and through which the inflatable slide may exit the packboard. Inthis regard, evacuation slide 104 may be configured to be deployed froman aircraft.

With reference to FIG. 3A and FIG. 3B, evacuation slide 104 isillustrated in a folded position, in accordance with variousembodiments. For example, when evacuation slide 104 is in the folded orstowed position, evacuation slide 104 may include a plurality of folds,including first fold 120 and second fold 122. A releasable restraint 150may aid in maintaining first fold 120 and/or second fold 122. Releasablerestraint 150 may aid in a staged deployment of evacuation slide 104.Evacuation slide 104 may unfold in response to releasable restraint 150separating.

In various embodiments, releasable restraint 150 may be configured toseparate in response to an internal pressure in evacuation slide 104.For example, a gas cylinder may supply a flow of pressurized fluid toevacuation slide 104 in response to evacuation slide 104 being deployed.Evacuation slide 104 may begin to inflate and an internal pressure ofevacuation slide 104 may increase. Releasable restraint 150 may maintainevacuation slide 104 in a folded position until the internal pressurehas increased above a predetermined threshold value. Releasablerestraint 150 may separate once the internal pressure of evacuationslide 104 has increased above the predetermined threshold value.Evacuation slide 104 may unfold in response to releasable restraint 150separating. In this regard, evacuation slide 104 may fully deploy inresponse to releasable restraint 150 separating.

In various embodiments, releasable restraint 150 may form a loop throughwhich a first strap 152 and a second strap 154 are located. First strap152 may be coupled between evacuation slide 104 and releasable restraint150. Second strap 154 may be coupled between evacuation slide 104 andreleasable restraint 150. In various embodiments, first strap 152 and/orsecond strap 154 may comprise a rope, tape, ribbon, webbing, or anyother suitable strap. In various embodiments, first strap 152 and/orsecond strap 154 may comprise nylon, ballistic nylon, polypropylene,polyester, cotton, or any other suitable material.

In various embodiments, a first cover 156 and/or a second cover 158 maysurround releasable restraint 150. Second cover 158 may surround atleast a portion of first cover 156. First cover 156 and second cover 158may comprise a fabric. For example, first cover 156 and second cover 158may comprise nylon, ballistic nylon, polypropylene, polyester, cotton,or any other suitable material.

With reference to FIG. 3C, releasable restraint 150, first strap 152,and second strap 154 are illustrated with first cover 156 and secondcover 158 omitted for clarity purposes. Releasable restraint 150 maycomprise a female fastener 160, a lead end 162, and a plurality of beads164 connected by a plurality of stems 166 extending along the lengthand/or body of releasable restraint 150 (i.e., between female fastener160 and lead end 162). Female fastener 160 is configured to receive andretain lead end 162 and one or more beads 164. Releasable restraint 150may comprise a single unibody member 151. Stated differently, femalefastener 160, lead end 162, beads 164, and stems 166 may comprise asingle unibody member 151. In various embodiments, releasable restraint150 may comprise a beaded cable tie, also referred to as a beaded ziptie. Releasable restraint 150 may comprise a thermoplastic material. Invarious embodiments, releasable restraint 150 may comprise nylon. Femalefastener 160, lead end 162, beads 164, and/or stems 166 may comprise athermoplastic material. In various embodiments, female fastener 160,lead end 162, beads 164, and/or stems 166 may comprise nylon. In variousembodiments, releasable restraint 150 may comprisepoly[imino(1,6-dioxohexamethylene)iminohexamethylene] (i.e., nylon 66)and/or poly(dodecano-12-lactam) (i.e., nylon 12). In variousembodiments, releasable restraint 150 may comprise a fluoropolymer. Forexample, releasable restraint 150 may comprise polytetrafluoroethylene(PTFE). In various embodiments, releasable restraint 150 may comprise aflame retardant.

In various embodiments, an end 180 of first strap 152 may be sewn orotherwise secured to first strap 152 to form a first loop 182. An end184 of second strap 154 may be sewn or otherwise secured to second strap154 to form a second loop 186. Loop 182 and loop 186 may couple firststrap 152 and second strap 154, respectively, to releasable restraint150, Lead end 162 of releasable restraint 150 may be extended throughfirst loop 182 and second loop 186 and fastened with one or more beads164 to female fastener 160.

With reference to FIG. 4, releasable restraint 150 is illustrated in an“unlocked” or “unsecured” configuration, in accordance with variousembodiments. In various embodiments, female fastener 160 may include anopening 168 and one or more pawls 170 configured to engage beads 164. Invarious embodiments, beads 164 may comprise a conical shape. In variousembodiments, beads 164 may comprise a spherical or other geometricshape. With momentary reference to FIG. 5A, beads 164 include a diameterD1. Diameter D1 and pawls 170 may be configured to prevent beads 164that have passed through female fastener 160 in a first direction,(i.e., have traveled through female fastener 160 in the direction ofarrow 172) from backing out female fastener 160 in a second directionopposite the first direction (i.e., from passing through female fastener160 in the direction of arrow 174). In other words, diameter D1 andpawls 170 may be configured so that lead end 162 and beads 164 may onlypass through female fastener 160 in one direction (i.e., the directionof arrow 172).

Returning to FIG. 4, releasable restraint 150 may comprise a pluralityof stems 166 connecting beads 164. Stems 166 each include a diameter D2.In various embodiments, the diameter D2 of each stem 166 alongreleasable restraint 150 may be inversely related to a distance the stemis from female fastener 160. In other words, stems 166 decrease indiameter in a direction of arrow 167. In various embodiments, a firststem more proximate to female fastener 160 may include a diameter thatis greater than a diameter of a second stem distal to female fastener160. For example, a diameter of stem 166 a may be greater than adiameter of stem 166 d, and a diameter of stem 166 d may be greater thana diameter of stem 166 g.

In various embodiments, each stem 166 may include a diameter that isdifferent from a diameter of the stems directly adjacent to it. In otherwords, a diameter of stem 166 a may be greater than a diameter of stem166 b; a diameter of stem 166 b may be greater than a diameter of stem166 c and less than a diameter of stem 166 a; a diameter of stem 166 cmay be greater than a diameter of stem 166 d and less than a diameter ofstem 166 b, and so on.

The diameter of each stem 166 may be directly related to the tensileforce and/or tensile load associated with separating or breaking thestem, such that a greater tensile force and/or tensile load isassociated with separating stems having a larger diameter. For example,a greater tensile force and/or tensile load may be associated withseparating stem 166 a than is associated with separating stem 166 b orthan is associated with separating stem 166 c. In various embodiments, afirst stem proximate to female fastener 160 (e.g., stem 166 c) mayseparate at a selected tensile load of between 80 pounds and 150 pounds(i.e., between 356 N and 667 N) and a second stem more distal to femalefastener 160 than the first stem (e.g., stems 166 d-166 h) may separateat a selected tensile load of between 10 pounds and 50 pounds (i.e.,between 44 N and 222 N). The selected tensile loads may increase alongsingle unibody member 151 in a direction opposite of arrow 167.

In various embodiments, stems 166 may be grouped by diameter and/ortensile strength. For example, a first group of stems 166 proximate tofemale fastener 160 (e.g., stems 166 a, 166 b, and 166 c) may have asame first diameter and/or same first tensile strength, and a secondgroup stems more distal to female fastener 160 than the first group ofstems (e.g., stems 166 d, 166 e, and 1660 may have a same seconddiameter and/or same second tensile strength, and a third group stemsmore distal to female fastener 160 than the first group of stems and thesecond group of stems (e.g., stems 166 g and 166 h) may have a samethird diameter and/or a same third tensile strength, and the firstdiameter and the first tensile strength are greater than the seconddiameter and the second tensile strength, respectively, and the seconddiameter and the second tensile strength are greater than the thirddiameter and third tensile strength, respectively.

In various embodiments, a first shape and/or a first color of a firstbead (e.g., bead 164 c) of releasable restraint 150 may indicate atensile strength of the stem (e.g., stem 166 c) connected to the firstbead, and a second shape and/or a second color of a second bead (e.g.,164 g) may indicate a tensile strength of the stem connected to thesecond bead. For example, a first shape (e.g., conical) and/or a firstcolor (e.g., red) of a bead 164 c may indicate a tensile load (e.g., 60pounds (267 N)) associated with separating stem 166 c, and a secondshape (e.g., spherical) and/or a second color (e.g., green) of bead 164g may indicate a tensile load (e.g., 15 pounds (68 N)) associated withseparating stem 166 g.

In various embodiments, a first cross-sectional shape and/or a firstcolor of a first stem may indicate a tensile strength of the first stem,and a second cross-sectional shape and/or a second color of a secondstem may indicate a tensile strength of the second stem. For example, afirst cross-sectional shape (e.g., circular) and/or a first color (e.g.,red) of stem 166 c may indicate a tensile load (e.g., 300 pounds (1334N)) associated with separating stem 166 c, and a second cross-sectionalshape (e.g., triangular) and/or a second color (e.g., green) of stem 166g may indicate a tensile load (e.g., 100 pounds (445 N)) associated withseparating stem 166 g.

In various embodiments, a first shape and/or a first color of a firstbead may indicate a diameter of the stem connected to the first bead,and a second shape and/or a second color of a second bead may indicate adiameter of the stem connected to the second bead. For example, a firstshape (e.g., conical) and/or a first color (e.g., red) of bead 164 c mayindicate a diameter (e.g., 0.13 inches (3.30 mm)) of stem 166 c, and asecond shape (e.g., hexagonal) and/or a second color (e.g., green) ofbead 164 g may indicate a diameter (e.g., 0.09 inches (2.29 mm)) of stem166 g.

In various embodiments, a first cross-sectional shape and/or a firstcolor of a first stem may indicate a diameter of the first stem, and asecond cross-sectional shape and/or a second color of a second stem mayindicate a diameter of the second stem. For example, a firstcross-sectional shape (e.g., circular) and/or a first color (e.g., red)of stem 166 c may indicate a diameter (e.g., 0.345 inches (8.763 mm)) ofstem 166 c, and a second cross-sectional shape (e.g., triangular) and/ora second color (e.g., green) of stem 166 g may indicate a diameter(e.g., 0.09 inches (2.29 mm)) of stem 166 g.

In various embodiments, a ratio of a tensile strength of a first stem(e.g., stem 166 b) to a tensile strength of a second stem (e.g. stem 166g), more distal to the female fastener 160 than the first stem, may bebetween 12:11 and 25:1. In various embodiments, a ratio of a tensilestrength of a first stem (e.g., stem 166 b) to a tensile strength of asecond stem (e.g. stems 166 g), more distal to the female fastener 160than the first stem, may be between 8:7 and 10:1. In variousembodiments, a ratio of a tensile strength of a first stem (e.g., stem166 b) to a tensile strength of a second stem (e.g., 166 g), more distalto the female fastener 160 than the first stem, may be between 3:2 and7:1. In various embodiments, a ratio of a tensile strength of a firststem (e.g., stem 166 b) to a tensile strength of a second stem (e.g.,166 g), more distal to the female fastener 160 than the first stem, maybe between 3:2 and 4:1.

In various embodiments, a ratio of a diameter of a first stem (e.g.,stem 166 c) to a diameter of a second stem (e.g., stem 166 h), moredistal to the female fastener 160 than the first stem, may be between13:12 and 8:1. In various embodiments, a ratio of a diameter of a firststem (e.g., stem 166 c) to a diameter of a second stem (e.g., stem 166h), more distal to the female fastener 160 than the first stem, may bebetween 6:5 and 7:1. In various embodiments, a ratio of a diameter of afirst stem (e.g., stem 166 c) to a diameter of a second stem (e.g., stem166 h), more distal to the female fastener 160 than the first stem, maybe between 6:5 and 2:1. In various embodiments, a ratio of a diameter ofa first stem (e.g., stem 166 c) to a diameter of a second stem (e.g.,stem 166 h), more distal to the female fastener 160 than the first stem,may be between 6:5 and 9:5.

In various embodiments, a first ratio of a tensile strength of a firststem (e.g., stem 166 b) to a tensile strength of a second stem (e.g.,stem 166 c) adjacent to the first stem may be less than a second ratioof the tensile strength of the first stem to a tensile strength of athird stem (e.g., stem 166 g) more distal to female fastener 160 thanthe first stem and second stem. In various embodiments, a first ratio ofa tensile strength of a first stem (e.g., stem 166 b) to a tensilestrength of a second stem (e.g., stem 166 c) adjacent to the first stemmay be between 8:7 and 2:1, and a second ratio of the tensile strengthof the first stem to a tensile strength of a third stem (e.g., stem 166g) more distal to female fastener 160 than the first stem and secondstem may be between 2:1 and 25:1. For example, a first ratio of atensile strength of stem 166 b to a tensile strength of stem 166 c maybe 6:5 and a second ratio of the tensile strength of stem 166 b to atensile strength of stem 166 g may be 7:1.

In various embodiments, a first ratio of a diameter of a first stem(e.g., stem 166 b) to a diameter of a second stem (e.g., stem 166 c)adjacent to the first stem may be less than a second ratio of thediameter of the first stem to a diameter of a third stem (e.g., stem 166g) more distal to female fastener 160 than the first stem and the secondstem. In various embodiments, a first ratio of a diameter of a firststem to a diameter of a second stem adjacent to the first stem may bebetween 13:12 and 6:5, and a second ratio of the diameter of the firststem to a diameter of a third stem (e.g., stem 166 g) more distal tofemale fastener 160 than the first stem and second stem may be between7:5 and 8:1. For example, a first ratio of a diameter of stem 166 b to adiameter of stem 166 c may be 12:11 and a second ratio of the diameterof stem 166 b to a diameter of stem 166 g may be 3:1.

With reference to FIG. 5A, releasable restraint 150 is illustrated in alocked position, in accordance with various embodiments. Lead end 162and one or more beads 164 may be inserted through and extend from femalefastener 160. Beads 164 may engage with female fastener 160 and/or pawl170. A load associated with releasing or breaking releasable restraint150 may be determined and/or defined by a tensile strength of the stem166L connected to the last bead 164L through female fastener 160.

With reference to FIG. 5B, releasable restraint 150 is illustrated in areleased or broken position, in accordance with various embodiments. Thestem 166L connected to the last bead 164L through female fastener 160may separate or break in response to a selected force and/or selectedtensile load, such as selected tensile load 190. Lead end 162 and thebeads 164 located through female fastener 160 may separate from thebeads 164 not located through female fastener 160 in response toselected tensile load 190.

In various embodiments, stems 166 may comprise frangible members. Stems166 may be figured to be frangible at a selected tensile load 190. Theselected tensile loads may increase along single unibody member 151 inthe direction of arrow 174 (FIG. 5A). Selected tensile load 190 may begenerated in response to an internal pressure of the evacuation slide104, with momentary reference to FIG. 3A, for example during inflation.In this regard, with momentary reference to FIG. 3B, releasablerestraint 150 may be in operable communication with evacuation slide104. In various embodiments, the stem 166L connected to the last bead164L located through female fastener 160 may define a weakest portion ofreleasable restraint 150 and as such define the point of separation ofreleasable restraint 150 when loaded during deployment of the evacuationslide 104. In this regard, the stem 166L connected to the last bead 164Llocated through female fastener 160 may be configured to withstandforces below a threshold value and may be configured to separate inresponse to forces above the threshold value.

In various embodiments, a number of beads 164 received by femalefastener 160 may indicate a load associated with releasing or breakingreleasable restraint 150. For example, with momentary reference to FIG.4, a tensile strength of the stems 166 connected to adjacent beads 164may differ by, for example, 10 pounds (44 N), such that stem 166 h mayseparate in response to a selected tensile load of, for example, 20pounds (89 N), and stem 166 g may separate in response to a selectedtensile load of, for example, 30 pounds (133 N), and stem 166 f, mayseparate in response to a selected tensile load of, for example, 40pounds (178 N), and stem 166 e, may separate in response to a selectedtensile load of, for example, 50 pounds (222 N), etc. In this regard,returning to FIG. 5B, the more beads 164 located through female fastener160, the greater the force and/or selected tensile load, associated withreleasing releasable restraint 150.

In various embodiments, a number of beads 164 received by femalefastener 160 may indicate a diameter of the stem 166L associated withreleasing or breaking releasable restraint 150. For example, withmomentary reference to FIG. 4, a diameter of adjacent stems 166 maydiffer by, for example, 0.01 inches (0.245 mm), such that stem 166 h mayhave a diameter of, for example, 0.05 inches (1.27 mm), and stem 166 gmay have a diameter of, for example, 0.06 inches (1.524 mm), and stem166 f, may have a diameter of, for example, 0.07 inches (1.778 mm), andstem 166 e, may have a diameter of, for example, 0.08 inches (2.032 mm),etc. In this regard, returning to FIG. 5B, the more beads 164 locatedthrough female fastener 160, the larger a diameter of the stem 166Lconnected to the last bead 164L through female fastener 160, and thusthe larger a diameter of the stem 166L associated with a releasing ofreleasable restraint 150.

In various embodiments, stems 166 along releasable restraint 150 mayvary in diameter such that releasable restraint 150 may be configured,based on the last bead 164L extended through female fastener 160, toseparate in response to a tensile force 190 of between 10 pounds and 250pounds (i.e., between 44 N and 1112 N), and in various embodiments inresponse to a tensile force 190 of between 10 pounds and 150 pounds(i.e., between 44 N and 667 N), and in various embodiments, in responseto a tensile force of between 10 pounds and 70 pounds (i.e., between 44N and 311 N). In various embodiments, stems 166 along releasablerestraint 150 may vary in diameter and/or tensile strength such thatreleasable restraint 150 may be configured, depending on the last bead164L extended through female fastener 160 (and thus the stem 166Lconnected to the last bead 164L located through female fastener 160), toseparate in response to any suitable tensile force 190 greater thanzero.

In various embodiments, a plurality of releasable restraints 150 may beprovided in parallel to withstand a predetermined force or selectedtensile load. For example, if it is desired that a restraint release orseparate at about 600 pounds (i.e., about 2669 N), two releasablerestraints configured to withstand 300 pounds (1334 N) may be providedin parallel to withstand the 600 pound (2669 N) force. In response to atensile force greater than 600 pounds (i.e., greater than 3669 N), thetwo restraints may release or break, allowing an evacuation system tofully deploy.

With reference to FIG. 6, a method 200 for restraining an evacuationslide is provided, in accordance with various embodiments. Method 200includes extending a releasable restraint through a first loop of afirst strap coupled to an evacuation slide (step 202). Method 200includes extending the releasable restraint through a second loop of asecond strap coupled to the evacuation slide (step 204). Method 200 mayinclude extending a lead end of the releasable restraint through afemale fastener of the releasable restraint (step 206). Method 200 mayinclude configuring the female fastener to receive and retain beads ofthe releasable restraint (step 207). Method 200 may include determininga last bead to extend through the female fastener based on a diameter ofa stem connected to the last bead (step 208). Method 200 may includeindicating a tensile strength of a first stem using at least one of acolor or a shape of a first bead (step 209).

In various embodiments, with combined reference to FIG. 3A, FIG. 3B,FIG. 4, FIG. 5B, and FIG. 6, step 202 may include extending releasablerestraint 150 through first loop 182 formed by first strap 152 coupledto evacuation slide 104. Step 204 may include extending releasablerestraint 150 through second loop 186 formed by second strap 154 coupledto the evacuation slide 104. Step 206 may include extending lead end 162of releasable restraint 150 through female fastener 160 of releasablerestraint 150. Step 207 may include configuring female fastener 160 toreceive and retain beads 164. Step 208 may include determining a lastbead 164L of releasable restraint 150 to extend through female fastener160 of releasable restraint 150 based on a diameter of a stem 166Lconnected to the last bead 164L. Step 209 may include indicating atensile strength of a first stem (e.g., 166 c) using at least one of acolor or a shape of a first bead (e.g., bead 164).

Benefits and other advantages have been described herein with regard tospecific embodiments. Furthermore, the connecting lines shown in thevarious figures contained herein are intended to represent exemplaryfunctional relationships and/or physical couplings between the variouselements. It should be noted that many alternative or additionalfunctional relationships or physical connections may be present in apractical system. However, the benefits, advantages, and any elementsthat may cause any benefit or advantage to occur or become morepronounced are not to be construed as critical, required, or essentialfeatures or elements of the disclosure. The scope of the disclosure isaccordingly to be limited by nothing other than the appended claims, inwhich reference to an element in the singular is not intended to mean“one and only one” unless explicitly so stated, but rather “one ormore.” Moreover, where a phrase similar to “at least one of A, B, or C”is used in the claims, it is intended that the phrase be interpreted tomean that A alone may be present in an embodiment, B alone may bepresent in an embodiment, C alone may be present in an embodiment, orthat any combination of the elements A, B and C may be present in asingle embodiment; for example, A and B, A and C, B and C, or A and 13and C.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “various embodiments”, “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described. After reading the description, itwill be apparent to one skilled in the relevant art(s) how to implementthe disclosure in alternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element is intended to invoke 35 U.S.C. 112(f)unless the element is expressly recited using the phrase “means for.” Asused herein, the terms “comprises”, “comprising”, or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus.

What is claimed is:
 1. A releasable restraint for an evacuation system,comprising: a first stem connected to a first bead; and a second stemconnected to a second bead, wherein a diameter of the second stem isdifferent from a diameter of the first stem.
 2. The releasable restraintof claim 1, wherein the releasable restraint comprises a single unibodymember.
 3. The releasable restraint of claim 2, wherein the singleunibody member comprises: a female fastener; a plurality of beadsincluding the first bead and the second bead; and a plurality of stems,including the first stem and the second stem, connecting the pluralityof beads, wherein the beads and the stems are configured to allow thebeads to move through the female fastener in a first direction whilepreventing the beads from moving through the female fastener in a seconddirection opposite of the first direction.
 4. The releasable restraintof claim 3, wherein the stems are configured to be frangible at aselected tensile load.
 5. The releasable restraint of claim 4, whereinthe selected tensile load increases along the single unibody member inthe second direction.
 6. The releasable restraint of claim 3, whereinthe releasable restraint is in operable communication with theevacuation system and a diameter of a stem connected to a last beadthrough the female fastener defines a load associated with releasing thereleasable restraint during deployment of the evacuation system.
 7. Thereleasable restraint of claim 1, wherein the releasable restraintcomprises nylon.
 8. The releasable restraint of claim 1, wherein atleast one of a color or a shape of at least one of the first bead or thefirst stem indicates a tensile strength of the first stem and isdifferent from at least one of a color or a shape of at least one of thesecond bead or the second stem.
 9. The releasable restraint of claim 1,wherein a ratio of the diameter of the first stem to the diameter of thesecond stem is between 6:5 and 7:1.
 10. The releasable restraint ofclaim 1, further comprising a third stem connected to a third bead,wherein a diameter of the third stem is different from the diameter ofthe first stem and the diameter of the second stem.
 11. An evacuationsystem, comprising: an evacuation slide; a first strap coupled to theevacuation slide; a second strap coupled to the evacuation slide; and areleasable restraint extending through the first strap and the secondstrap, the releasable restraint comprising, a first stem connected to afirst bead, and a second stem connected to a second bead, wherein adiameter of the second stem is different from a diameter of the firststem.
 12. The evacuation system of claim 11, wherein the releasablerestraint further comprises a female fastener configured to receive andretain a plurality of beads of the releasable restraint, the pluralityof beads including the first bead and the second bead, wherein adiameter of a stem connected to a last bead received by the femalefastener defines a load associated with releasing the releasablerestraint during deployment of the evacuation slide.
 13. The evacuationsystem of claim 11, wherein at least one of a color or a shape of thefirst bead indicates the diameter of the first stem and is differentfrom at least one of a color or a shape of the second bead.
 14. Theevacuation system of claim 11, wherein the first stem is configured toseparate in response to a first tensile force and the second stem isconfigured to separate in response to a second tensile force greaterthan the first tensile force.
 15. The evacuation system of claim 14,wherein the diameter of the first stem is between 0.05 inches and 0.13inches.
 16. The evacuation system of claim 15, wherein the diameter ofthe second stem is between 0.09 inches and 0.345 inches.
 17. A methodfor restraining an evacuation slide, comprising: extending a releasablerestraint through a first strap coupled to the evacuation slide, thereleasable restraint comprising, a first stem connected to a first bead,and a second stem connected to a second bead, wherein a diameter of thesecond stem is different from a diameter of the first stem; andextending the releasable restraint through a second strap coupled to theevacuation slide.
 18. The method of claim 17, further comprisingconfiguring a female fastener of the releasable restraint to receive andretain a plurality of beads of the releasable restraint, the pluralityof beads including the first bead and the second bead, wherein adiameter of a stem connected to a last bead received by the femalefastener defines a load associated with releasing the releasablerestraint.
 19. The method of claim 18, further comprising indicating atleast one of a diameter or a tensile strength of the first stem using atleast one of a color or a shape of the first bead.
 20. The method ofclaim 17, wherein a ratio of the diameter of the first stem to thediameter of the second stem is between 6:5 and 7:1.